Methods and apparatus for transporting data cartridges between adjacent cartridge libraries

ABSTRACT

An apparatus and method for transporting data cartridges between cartridge libraries. A data cartridge is received by a data cartridge transport device, pivoted, and then ejected to a cartridge sleeve of a second cartridge library. In one embodiment, the data cartridge transport device includes a pivot assembly; a cartridge sleeve, mounted to the pivot assembly; a cartridge eject mechanism, operably associated with the cartridge sleeve; a drive assembly; and a clutch assembly. The clutch assembly moves between first and second positions, wherein movement of the clutch assembly to the first position engages the pivot assembly with the drive assembly, thereby enabling pivoting of the cartridge sleeve, and wherein movement of the clutch assembly to the second position engages the cartridge eject mechanism with the drive assembly, thereby enabling ejection of a data cartridge from the cartridge sleeve.

FIELD OF THE INVENTION

[0001] The invention pertains to the storage of data cartridges incartridge libraries, and more particularly, to the integration andexpansion of such libraries.

BACKGROUND OF THE INVENTION

[0002] There are many types of data storage systems available today.Some of these systems store data cartridges (e.g., DLT cartridges) atknown locations, and retrieve desired data cartridges from the knownlocations so that data may be written to or read from the datacartridges. Such data storage systems are often referred to as“cartridge libraries”, particularly if they can accommodate a largenumber of data cartridges.

[0003] A typical cartridge library may include one or more differenttypes of cartridge-receiving devices for holding the library's variousdata cartridges. One type of cartridge-receiving device may comprise acartridge storage rack, while another type of cartridge-receiving devicemay comprise a cartridge read/write device or “drive”. The cartridgestorage racks serve to provide storage locations for data cartridgesthat are not currently in use. Often, a cartridge storage rack will bedesigned to hold a number of cartridge magazines, with each magazineholding a predetermined subset of data cartridges. In this manner, it iseasier to add and/or remove data cartridges from a cartridge library. acartridge library may also be provided with a movable cartridge-engagingassembly or “picker” for transporting data cartridges between alibrary's various cartridge-receiving devices (e.g., between cartridgestorage racks and cartridge drives). A typical cartridge-engagingassembly may also be provided with a plunge mechanism or “thumbassembly” for engaging the various data cartridges contained in thecartridge-receiving devices and drawing them into the cartridge-engagingassembly. A positioning system associated with the cartridge-engagingassembly may be used to move the cartridge-engaging assembly between thevarious cartridge-receiving devices.

[0004] Cartridge libraries of the type described above are usuallyconnected to a host computer system that reads and writes the datacartridges. For example, if the host computer system issues a requestfor data contained on a particular data cartridge, a control systemassociated with the cartridge library will actuate the positioningsystem to move the cartridge-engaging assembly along the cartridgestorage racks until the cartridge-engaging assembly is positionedadjacent a desired data cartridge. The plunge mechanism associated withthe cartridge-engaging assembly may then extend, engage the datacartridge, remove the data cartridge from its cartridge storage rack,and then retract to draw the data cartridge into the cartridge-engagingassembly. Thereafter, the positioning system may be actuated to move thecartridge-engaging assembly to an appropriate cartridge drive. Onceproperly positioned adjacent the cartridge drive, the plunge mechanismmay extend to insert the selected data cartridge into the cartridgedrive so that the host computer may thereafter read and/or write thedata cartridge. After the read/write operation is complete, the plungemechanism may be actuated to remove the data cartridge from thecartridge drive, and the cartridge-engaging assembly may be actuated toreturn the data cartridge to its cartridge storage rack.

[0005] A cartridge library encompassing many of the above features isdisclosed in U.S. Pat. No. 6,025,972 of Schmidtke et al. entitled“Multi-Plane Translating Cartridge Handling System”. This patent ishereby incorporated by reference for all that it discloses.

[0006] The capacity of a cartridge library may be expanded up to acertain point by filling each of its cartridge storage racks with datacartridges. Often, however, additional storage capacity is needed. Somecartridge libraries, such as the HP Surestore 2/20 series cartridgelibrary (made by Hewlett-Packard Company of Palo Alto, Calif.) holds upto twenty data cartridges. The twenty cartridge capacity is dividedamong two cartridge storage racks, each of which holds two cartridgemagazines, and each magazine of which holds five individual datacartridges. Each of the cartridge storage racks is supported by slidesthat form the basis of a drawer. To add or remove cartridges from acartridge library, one of its drawers is opened, a cartridge magazine isadded or removed, and the drawer is closed.

[0007] Once the capacity of the above-described cartridge library isexceeded, cartridge handling capacity may be increased by stackingadditional cartridge library modules on top of the existing module, andthen integrating all of the stacked modules to form a single, highercapacity cartridge library. There is a limit, however, to the number ofcartridge library modules that may be stacked.

SUMMARY OF THE INVENTION

[0008] For the purpose of further increasing the capacity of a cartridgelibrary, the inventors have devised what they believe to be novelmethods and apparatus for transporting data cartridges between adjacentcartridge libraries. By transporting data cartridges between adjacentcartridge libraries, the storage capacity of a single cartridge librarymay be increased by providing access to additional cartridge storageracks and/or additional cartridge drives. In a cartridge library havingdrives that often sit unused, increasing the number of cartridge storageracks associated with the library can provide for more efficient use ofthe library's drives. On the other hand, in a cartridge library havingdrives which are overused, increasing the number of drives associatedwith the library can provide for more efficient access to the library'sdata. Even when a library's access to cartridge storage racks and drivesare increased in a proportional manner, the mere association of morestorage racks and more drives is likely to improve the use of, andaccess to, a library's components and data.

[0009] In a first embodiment of the invention, a data cartridgetransport system comprises first and second data cartridge transportdevices. The first data cartridge transport device comprises a pivotassembly, a cartridge sleeve that is mounted to the pivot assembly, acartridge eject mechanism that is operably associated with the cartridgesleeve, and a control system. The control system alternately operatesthe pivot assembly and the cartridge eject mechanism.

[0010] In a second embodiment of the invention, a data cartridgetransport device comprises a pivot assembly, a cartridge sleeve that ismounted to the pivot assembly, a cartridge eject mechanism that isoperably associated with the cartridge sleeve, a drive assembly, and aclutch assembly. The clutch assembly moves between first and secondpositions, wherein movement of the clutch assembly to its first positioncauses the pivot assembly to engage the drive assembly, thereby enablingpivoting of the cartridge sleeve. Movement of the clutch assembly to itssecond position then causes the cartridge eject mechanism to engage thedrive assembly, thereby enabling the ejection of a data cartridge fromthe cartridge sleeve.

[0011] In yet another embodiment of the invention, a method oftransporting data cartridges between cartridge libraries comprisesreceiving a data cartridge stored in a first cartridge library, pivotingthe data cartridge, and ejecting the data cartridge to a cartridgesleeve of a second cartridge library.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Illustrative and presently preferred embodiments of the inventionare illustrated in the drawings, in which:

[0013]FIG. 1 illustrates two adjacent cartridge libraries;

[0014]FIG. 2 illustrates a prior art cross-section of the FIG. 1cartridge libraries, wherein adjacent cartridge library modules functionindependently from one another;

[0015]FIG. 3 illustrates a cross-section of FIG. 1 showing the presentinvention, wherein one of the cartridge libraries comprises a pivotingdata cartridge transport device, and the other cartridge librarycomprises a pass-through cartridge transport device;

[0016]FIG. 4 illustrates an enlarged view of the FIG. 3 data cartridgetransport system;

[0017]FIG. 5 illustrates a first alternative to the FIG. 4 datacartridge transport system, wherein the pivoting data cartridgetransport device comprises an off-center pivot;

[0018]FIG. 6 illustrates an alternate view of the FIG. 5 data cartridgetransport system, wherein the pivoting data cartridge transport devicehas pivoted so as to interface with a pass-through data cartridgetransport device;

[0019]FIG. 7 illustrates a second alternative to the FIG. 4 datacartridge transport system, wherein a pivoting data cartridge transportdevice is mounted between the two adjacent cartridge libraries, andwherein each of the two adjacent cartridge libraries comprises apass-through data cartridge transport device;

[0020]FIG. 8 illustrates (in elevation) a preferred embodiment of thepivoting data cartridge transport device illustrated in FIGS. 3 & 4,wherein the device is in eject mode;

[0021]FIG. 9 illustrates the FIG. 8 device in pivot mode;

[0022]FIG. 10 illustrates an enlarged plan view of the cartridge ejectmechanism shown in FIGS. 8 & 9;

[0023]FIG. 11 illustrates a plan view of the pivot gear shown in FIGS. 8& 9;

[0024]FIG. 12 illustrates a perspective view of the cartridge sleeveblade which slides in the channel of the FIG. 11 pivot gear; and

[0025]FIG. 13 illustrates a plan view of the noose shown in FIGS. 8 & 9.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0026]FIG. 1 illustrates two adjacent cartridge libraries 104, 106. Eachcartridge library 104, 106 comprises a number of modules 100,102,108-118 that are stacked and integrated to form a single, highercapacity, cartridge library 104, 106. Typically, the number of modules100, 108-112 that may be stacked to form a single cartridge library 104is limited to a relatively small number of modules (e.g., sevenmodules). In FIG. 1, each module 100 comprises two drawers 120, 122,with each drawer 120, 122 holding two cartridge magazines. Eachcartridge magazine holds five data cartridges so that each of the FIG. 1cartridge libraries 104, 106, in turn, holds up to 80 data cartridges(i.e., 4 modules×2 drawers/module×2 magazines/drawer×5cartridges/magazine). If access to more than the 80 data cartridges heldby one cartridge library 104 is desired, an additional cartridge library106 may be acquired.

[0027] A disadvantage of the FIG. 1 library system is that the twoadjacent cartridge libraries 104, 106 operate distinctly. For example,each of the cartridge libraries 104, 106 must comprise its own set ofdrives, even though a library user may only need to access a smallnumber of cartridges at any one time. In addition, access to aparticular data cartridge may be limited by the availability of drivesin a particular one of the cartridge libraries 104, 106, even though theother cartridge library may have drives that remain unused.

[0028]FIG. 2 illustrates a cross-section of the FIG. 1 cartridgelibraries 104, 106, wherein adjacent modules 100, 102 of the cartridgelibraries 104, 106 function as independent systems. The modules 100, 102are shown to be constructed in a similar manner, but they need not be.Each module 100, 102 (or “cartridge library” as they will be hereinafterreferred to) may comprise a cartridge-engaging assembly or “picker” 200for transferring data cartridges 202 between one or morecartridge-receiving devices 204-210 mounted within the cartridge library100.

[0029] The cartridge-receiving devices may comprise one or morecartridge storage racks 204, 206 and one or more cartridge read/writedevices or “drives” 208, 210. The cartridge storage racks 204, 206 serveto provide storage locations for data cartridges 202, 220, 222, 224, 226that are not currently in use.

[0030] Often, cartridge storage racks 204, 206 will be designed to holda number of cartridge magazines 212, 214, 216, 218, with each magazine212-218 holding a predetermined subset of data cartridges 202, 220-226.In this manner, it is easier to add and/or remove data cartridges 202,220-226 from a cartridge library 100.

[0031] The various cartridge-receiving devices (e.g., the cartridgestorage racks 204, 206 and the cartridge read/write devices 208, 210)may be positioned at various locations within a cartridge library 100 sothat they define a generally U-shaped configuration.

[0032] The cartridge-engaging assembly 200 is adapted to 1) engage adata cartridge 202 contained in a cartridge-receiving device 204-210,and then 2) draw the data cartridge 202 into the cartridge-engagingassembly for transport to a different cartridge-receiving device204-210. Movement of the cartridge-engaging assembly 200 may be achievedvia an actuator system 246 that moves the cartridge-engaging assembly200 along a U-shaped path of a cartridge positioning system 248.

[0033] By way of example, the cartridge positioning system 248 may be ofthe type shown and described in U.S. Pat. No. 6,025,972 (referred tosupra). The cartridge positioning system 248 disclosed therein maycomprise a generally rectangularly-shaped structure having a pair ofopposed side portions 228 and 230 and an end portion 232. A pair ofcartridge storage racks 204, 206 may be positioned adjacent the twoopposed sides 228, 230 of the cartridge positioning system 248.Similarly, a pair of cartridge read/write devices 208, 210 may bepositioned adjacent the end 232 of the cartridge positioning system 248.

[0034] The cartridge positioning system 248 may also comprise a lowerplate 234 having a U-shaped guide member or channel 236 formed thereinfor guiding the cartridge-engaging assembly 200 along a generallyU-shaped path 238 so that the cartridge-engaging assembly 200 may accessthe data cartridges 202, 220-226 contained in the various cartridgestorage racks 204, 206 and cartridge read/write devices 208, 210.

[0035] As previously stated, the cartridge-engaging assembly 200 may bemoved along the U-shaped guide member 236 by an actuator system 246. Forexample, the actuator system 246 may move the cartridge-engagingassembly 200 between a first position 240 adjacent the first sideportion 228 of the positioning system 248, a second position 240′adjacent the end portion 232 of the positioning system 248, and a thirdposition 240″ adjacent the second side portion 230 of the positioningsystem 248 (i.e., the cartridge-engaging assembly 200 may be moved alongthe generally U-shaped path 238).

[0036] The actuator system 246 may comprise a rack-and-pinion drivesystem having a U-shaped gear rack 242 mounted adjacent the U-shapedguide member 236 in the lower plate 234. A lower pinion gear 244 may bemounted to the cartridge-engaging assembly 200 so that it engages theU-shaped gear rack 242. A suitable drive motor (not shown) may be usedto drive the pinion gear 244 and thereby move the cartridge-engagingassembly 200 along the U-shaped path 238.

[0037] The foregoing description of a cartridge library 100 andcartridge positioning system 248 is provided so that one may betterunderstand one environment in which the data cartridge transport devicesto be described hereafter may be used.

[0038] The ability to transport data cartridges between two or moreadjacent cartridge libraries 104, 106 would therefore be desirable.

[0039] In accordance with the invention, FIG. 3 illustrates analternative cross-section of the FIG. 1 cartridge libraries 100,102,wherein one cartridge library 100 has been modified to hold a first datacartridge transport device 300, and the other cartridge library 102 hasbeen modified to hold a second cartridge transport device 302. FIG. 4illustrates an enlarged view of the FIG. 3 cartridge transport system300, 302.

[0040] In FIGS. 3 & 4, the first data cartridge transport device 300 isa pivoting transport device, and the second data cartridge transportdevice 302 is a pass-through transport device. In this manner, a datacartridge 202 stored in one of the cartridge libraries 100 may beretrieved by the cartridge-engaging assembly 200, placed in a cartridgesleeve 304 of the first data cartridge transport device 300, pivoted 180degrees, ejected to the second data cartridge transport device 302, andthen accessed by a cartridge-engaging assembly 306 of the othercartridge library 102. The transported data cartridge 202 is pivoted sothat it is correctly oriented for engagement by the cartridge-engagingassembly 306 of the library 102 to which it is transported.

[0041] The first data cartridge transport device 300 may comprise apivot assembly 308 and a cartridge sleeve 304. The cartridge sleeve 304is mounted to the pivot assembly 308 so that it pivots with the pivotassembly 308. In FIGS. 3 & 4, the cartridge sleeve 304 is shown to pivotclockwise. However, the choice of pivot direction (e.g., clockwise orcounter-clockwise) is largely arbitrary. A cartridge eject mechanism 800(shown in FIGS. 8 & 9, but not in FIGS. 3 & 4) is operably associatedwith the cartridge sleeve 304 so that a data cartridge 202 may beejected from the cartridge sleeve 304. The data cartridge transportdevice 300 also comprises a control system 802 (again shown in FIGS. 8 &9, but not in FIGS. 3 & 4). The control system 802 is provided foralternately operating the pivot assembly 308 and the cartridge ejectmechanism 800. Operation of the pivot assembly 308 causes the cartridgesleeve 304 to pivot, whereas operation of the cartridge eject mechanism800 causes a data cartridge 202 to be ejected from the cartridge sleeve304. Ejection of a data cartridge 202 from the first data cartridgetransport device 300 allows the data cartridge 202 to be received by thesecond data cartridge transport device 302.

[0042] The second data cartridge transport device 302 may be constructedsimilarly to the first 300, but is preferably constructed as apass-through device. Since a data cartridge need only be pivoted 180degrees as it is transported from one cartridge library 100 to another102, only one of two adjacent cartridge libraries 100, 102 need comprisea pivoting data cartridge transport device 300.

[0043] Note that the data cartridge transport system illustrated in FIG.4 requires the first data cartridge transport device 300 to be an activedevice. That is, it must be capable of ejecting a cartridge 202 to thesecond data cartridge transport device 302. However, the second datacartridge transport device 302 may be constructed as either a passive oractive device. A passive pass-through device is similar to a typicalcartridge storage rack, in that data cartridges must be fully insertedinto it, and it has no way of ejecting a data cartridge (i.e.,cartridges must be extracted from it using a picker 306 or the like). Anactive pass-through device, on the other hand, comprises an activecartridge-receiving mechanism for pulling a cartridge into the device,and/or an active cartridge eject mechanism for ejecting a cartridge fromthe device. An active pass-through device is advantageous in that 1) itmay grab a data cartridge which has yet to be fully received into thedevice, and then pull the cartridge into the device, and/or 2) it mayeject a data cartridge to thereby assist in enabling multi-directionalcartridge transports (i.e., transport of a cartridge from a firstcartridge library 100 to a second 102, and from the second cartridgelibrary 102 to the first 100).

[0044] If desired, the second data cartridge transport device 302 shownin FIG. 3 may also be a pivoting device 300. It might be desirable forthe second data cartridge transport device 302 to be an active, pivotingdevice 300 if, for example, uniformity of manufacturing or 2-waycartridge transport is desired.

[0045] The data cartridge transport devices 300, 302 shown in FIG. 3 arepreferably sized to be held by cartridge storage racks 204, 206,similarly to cartridge magazines 212-218, 310, 312. In this manner, thetransport devices 300, 302 may be purchased as accessories for adjacentcartridge libraries 100, 102, and may be inserted into and/or removedfrom a pair of adjacent cartridge libraries 100,102 as necessary.

[0046] As seen more clearly in FIG. 4, holes 404, 406 may need to be cutinto the walls 400, 402 of adjacent cartridge libraries 100, 102 so thatdata cartridges may be passed between the libraries. However, in somecases, these holes 404, 406 may already exist.

[0047]FIG. 5 illustrates a first alternative to the FIG. 4 datacartridge transport system, wherein the pivoting data cartridgetransport device 500 comprises an off-center pivot 504 (i.e., a pivotwhich is off-center with respect to an axis of the transport device'spivot assembly 308). FIG. 6 shows an alternate view of the FIG. 5 datacartridge transport system, wherein the pivoting data cartridgetransport device 500 has pivoted so as to interface with a pass-throughdata cartridge transport device 502. The arrangement illustrated inFIGS. 5 & 6 is advantageous in instances where only the first datacartridge transport device 500 is active and the second data cartridgetransport device 502 is a passive device that is unable to activelyreceive a cartridge. The FIGS. 5 & 6 arrangement is also advantageouswhen it is desired to bridge more than a “de minimis” gap between twoadjacent cartridge libraries 100, 102. Since the off-center pivot 504 ofthe first data cartridge transport device 500 enables the cartridgesleeve 304 of the first data cartridge transport device 500 to pivotwithin a short distance of the second data cartridge transport device500, the cartridge eject mechanism 800 of the first data cartridgetransport device 500 may be used to fully insert a data cartridge 202into the second data cartridge transport device 502 (or come “closeenough” to inserting the data cartridge 202 fully into the second datacartridge transport device 502).

[0048] Note in FIG. 5 that if the cartridge-engaging assembly 200 of thesecond cartridge library 102 (i.e., the library 102 containing thesecond data cartridge transport device 502) is capable of pushing acartridge 200 a little more than completely into the second datacartridge transport device 502, then the first data cartridge transportdevice 500 will be able to grab the cartridge 200 by means of acartridge-receiving mechanism (e.g., a cartridge eject mechanism 800operated in a reverse direction).

[0049]FIG. 7 illustrates a second alternative to the FIG. 4 datacartridge transport system, wherein a pivoting data cartridge transportdevice 700 is mounted between two adjacent cartridge libraries 100, 102,and wherein each of the two adjacent cartridge libraries 100, 102comprises a pass-through data cartridge transport device 702, 704. Thepivoting data cartridge transport device 700 is similar to thatdisclosed in FIGS. 3 & 4, but for the location in which it is mounted.At a minimum, the FIG. 7 apparatus allows data cartridges to betransported from a first cartridge library 100 to a second cartridgelibrary 102. However, if both of the pass-through transport devices areactive devices, cartridges may not only be transported from a firstcartridge library 100 to a second 102, but also from the secondcartridge library 102 to the first 100.

[0050]FIGS. 8 & 9 illustrate (in elevation) a preferred embodiment ofthe pivoting data cartridge transport device 300 illustrated in FIGS. 3& 4. In FIG. 8, the device is shown in eject mode. In FIG. 9, the deviceis shown in pivot mode. The device comprises a pivot assembly 308, acartridge sleeve 304 (with entry and exit facing perpendicular tofigure), a cartridge eject mechanism 800, and a control system 802. Thecartridge sleeve 304 is mounted to the pivot assembly 308 so that itpivots with the pivot assembly 308. The cartridge eject mechanism 800 isoperably associated with the cartridge sleeve 304 so that it may ejectcartridges which are held by the cartridge sleeve 304. The controlsystem 802 is provided for alternately operating the pivot assembly 308(to thereby pivot the cartridge sleeve 304 and a cartridge held therein)and the cartridge eject mechanism 800 (to thereby eject a cartridge fromthe cartridge sleeve 304).

[0051] In a preferred embodiment, the pivot assembly 308 comprises apivot gear 804 coupled to a pivot 806. The pivot gear 804 has aplurality of teeth on its circumference. The pivot 804 is preferably ofinverted-T cross-section such that it is capable of sliding in a channel808. The channel 808 may be formed in a housing 810 that is provided forthe data cartridge transport device 300.

[0052] Mounted to the pivot gear 804 is the cartridge sleeve 304. Asshown in FIGS. 11 & 12, a channel 1100 is cut into the top surface ofthe pivot gear 804. Within this channel 1100 slides a blade 1200. Theblade 1200 is mounted to the underside of the cartridge sleeve 304. Whenthe blade 1200 is fit into the channel 1100, the cartridge sleeve 304 ismounted to the pivot gear 804 in such a manner that the cartridge sleeve304 will pivot with the pivot gear 804. However, note that the channel1100 is preferably of greater length than the blade 1200. As a result ofthis arrangement, the cartridge sleeve 304 may not only be pivoted withthe pivot gear 804, but the cartridge sleeve 304 may also slide withinthe pivot gear 804 (for a purpose which has yet to be described).Alternatively, the cartridge sleeve 304 could comprise a channel, andthe pivot gear 804 could comprise a blade.

[0053] In operation, the pivot assembly 308 and cartridge sleeve 304function as follows. When the pivot 806 of the pivot assembly 308 isslid to a first position within its channel 808, as shown in FIG. 9, thepivot gear 804 is brought into engagement with a drive gear 812 of thecontrol system 802. Operation of the control system 802 therefore causesthe pivot gear 804 and cartridge sleeve 304 to pivot. When the cartridgesleeve 304 has been pivoted 180 degrees, the control system 802 stopsdriving the drive gear 812, and instead operates a clutch assembly 814,816, 818. By operation of the clutch assembly 814-818, a noose 820 whichencircles the pivot 806 of the pivot assembly 308 pushes the pivot 806and pivot gear 804 away from the control system's drive gear 812 so asto disengage the pivot gear 804 from the drive gear 812 (see FIGS. 8, 9& 13). When pushed by the noose 820, the pivot 806 migrates toward itssecond position in the channel 808 of the pivot gear 804, as shown inFIG. 8. Note, however, that the cartridge sleeve 304 preferably does notmove to a second position, as does the pivot gear 804. This is becausethe pivot gear 804 is preferably firmly attached to the pivot 806, butthe cartridge sleeve is slidably mounted on the pivot gear 804 (i.e.,via the channel 808 and blade 1200).

[0054] In an alternate clutch arrangement, the pivot gear 804 may befixedly attached to the cartridge sleeve 304, and the drive gear 812 maybe moved so as to disengage the pivot gear 804. The drive gear 812 mightbe moved in a variety of ways, including, by sliding in relation to thedrive shaft 838, or by movement of the drive shaft 838 with respect tothe bracket 842 which provides its support.

[0055] The cartridge eject mechanism 800 will now be discussed. Aspreviously mentioned, the cartridge eject mechanism 800 is operablyassociated with the cartridge sleeve 304 so that it may eject cartridgesthat are held by the cartridge sleeve 304. In a preferred embodiment,the cartridge eject mechanism 800 is mounted, in part, to the topportion of the cartridge sleeve 304. The portion of the cartridge ejectmechanism 800 which is mounted to the top portion of the cartridgesleeve 304 descends into the cartridge sleeve 304 so that it may grip,grab, push or otherwise contact a cartridge 202 which is held by thecartridge sleeve 304 (see especially, FIG. 10). In FIGS. 8-10, theportion of the cartridge eject mechanism 800 which is mounted to thecartridge sleeve 304 comprises a plurality of ejection rollers 1000-1014and a cartridge ejection gear train 1016-1030. Parts 1016-1022 of thegear train 1016-1030 are fixedly attached to the ejection rollers1000-1014 so that the gear train 1016-1030 drives the ejection rollers1000-1014.

[0056] Another portion of the cartridge eject mechanism 800 is mountedto the housing 810 in which the data cartridge transport device 300 ismounted. This second portion of the cartridge eject mechanism 800comprises a drive shaft 822, a pair of drive gears 824, 832, and anidler gear 826. The drive shaft 822 may be supported by a pair ofbrackets 828, 830 which extend from the transport device's housing 810.One of the drive gears is preferably a pinion gear 824, and is fixedlyand axially mounted to the drive shaft 822. The other drive gear 832preferably has teeth around its circumference, is fixedly and axiallymounted to the drive shaft 822, and is able to engage a gear of thecartridge ejection gear train 1016-1030 so as to operate the cartridgeejection gear train when the drive shaft 822 is rotated. The idler gear826 is axially mounted to the drive shaft 822 in a free-wheelingarrangement such that its only purpose is to help align the drive shaftwith a drive gear 834 of the control system 802 when the cartridgeejection mechanism 800 is engaged and operated by the control system 802(FIG. 8).

[0057] The drive shaft 822 of the cartridge eject mechanism 800 may becoupled to a clutch assembly 814-818 of the control system 802 via apivot, slip 837 or the like. In this manner, the drive shaft 822 mayturn, yet the clutch assembly 814-818 may slide the drive shaft 822within its brackets 828, 830 so as to engage or disengage the driveshaft's pinion gear 824 with a drive gear (e.g., a ring gear 834) of thecontrol system 802. FIG. 8 illustrates engagement of the ring and piniongears 834, 824. FIG. 9 illustrates disengagement of the ring and piniongears 834, 824. Note that in FIG. 9, not only are the ring and piniongears 834, 824 disengaged, but the drive gear 832 which operates thecartridge ejection gear train 1016-1030 is disengaged from the geartrain 1016-1030.

[0058] In the alternate clutch assembly mentioned previously, the driveshaft 822 of the cartridge eject mechanism 800 would necessarilycomprise a pinion gear 824 and idler gear 826 which engaged the drivegear 834 from the operate direction (i.e., from the right in FIGS. 8 &9).

[0059] While a preferred embodiment of a cartridge eject mechanism 800is shown to comprise ejection rollers 1000-1014, a cartridge ejectmechanism 800 may alternatively comprise other ejections means, such asan ejection conveyor, an ejection push rod, etc.

[0060] A preferred embodiment of a transport device's control system 802will now be discussed in detail. In FIGS. 8 & 9, the control system 802illustrated therein comprises a drive assembly 812, 834-840 and a clutchassembly 814-818. The drive assembly 812, 834-840 preferably comprises asingle drive motor 836 and a plurality of gears 812, 834, 840, with thesingle drive motor 836 driving all of the gears 812, 834, 840. Some ofthe gears 812, 840 are driven via a drive shaft 838 that extends fromthe drive motor 836. One of the gears 812 that is driven by the drivemotor 836 serves to engage and drive the pivot gear 804 when the pivotassembly 308 is engaged with the drive assembly 812, 834-840. Another ofthe gears 834 which is driven by the drive motor 836 serves to engageand drive the pinion gear 824 of the cartridge eject mechanism 800 whenthe cartridge eject mechanism 800 is engaged with the drive assembly812, 834-840. Note that the pivot assembly drive gear 812 is preferablymounted directly to the drive motor's drive shaft 838, whereas thecartridge eject mechanism's drive gear 834 is preferably mounted to thetransport device's housing 810. The remaining gears 840 which are drivenby the drive motor 836 may serve as a gear ratio conversion assembly.Although FIGS. 8 & 9 only show a gear ratio conversion assembly 840driving the cartridge eject mechanism 800, such an assembly could alsobe used for driving the pivot assembly 308.

[0061] The drive motor 836 and drive shaft 838 of the drive assembly812, 834-840 may be supported by a bracket 842 extending from thetransport device's housing 810.

[0062] The control system 802 may also comprise a clutch assembly814-818. The clutch assembly 814-818 may in turn comprise a solenoid 814and a pivot arm 818. The pivot arm 818 is preferably coupled to thesolenoid 814, the pivot assembly 308, and the cartridge eject mechanism800. The pivot arm 818 may be coupled to the solenoid 814 via a plunger816; the pivot arm 818 may be coupled to the pivot assembly 308 via anoose 820; and the pivot arm 818 may be coupled to the cartridge ejectmechanism 800 via a slip 837. The pivot point 844 of the pivot arm 818may be mounted on a bracket 842 for supporting the solenoid 814, drivemotor 836 and drive shaft 838 (with the pivot arm 818 extending througha cavity in the bracket 842).

[0063] The clutch assembly 814-818 is movable between first and secondpositions. The first position is achieved when the solenoid 814 retractsits plunger 816 (see FIG. 9). In this position, 1) the drive shaft 822of the cartridge eject mechanism 800 is disengaged from the controlsystem's drive assembly 812, 834-840, and 2) the pivot gear 804 of thepivot assembly 308 is engaged with the control system's drive assembly812, 834-840. In this position, the cartridge sleeve 304 may be pivoted.

[0064] The second position of the clutch assembly 814-818 is achievedwhen the solenoid 814 extends its plunger 816 (see FIG. 8). In thisposition, 1) the drive shaft 822 of the cartridge eject mechanism 800 isengaged with the control system's drive assembly 812, 834-840, and 2)the pivot gear 804 of the pivot assembly 308 is disengaged from thecontrol system's drive assembly 812, 834-840. In this position, acartridge 202 may be ejected from the cartridge sleeve 304.

[0065] The drive motor 836 and solenoid 814 may be powered by abackplane (not shown) to which other electronics of a cartridge library100 are connected.

[0066] One should now appreciate how the alternate driving of a pivotassembly 308 and a cartridge eject mechanism 800 enables the transportof a data cartridge 202 between cartridge libraries.

What is claimed is:
 1. A data cartridge transport device, comprising: apivot assembly; a cartridge sleeve, mounted to said pivot assembly; acartridge eject mechanism, operably associated with said cartridgesleeve; a drive assembly; and a clutch assembly which moves betweenfirst and second positions, wherein movement of said clutch assembly tosaid first position engages said pivot assembly with said driveassembly, thereby enabling pivoting of said cartridge sleeve, andwherein movement of said clutch assembly to said second position engagessaid cartridge eject mechanism with said drive assembly, therebyenabling ejection of a data cartridge from said cartridge sleeve.
 2. Adata cartridge transport device as in claim 1, wherein said pivotassembly comprises a pivot which is off-center with respect to an axisof said cartridge sleeve when said pivot assembly is engaged with saiddrive assembly.
 3. A data cartridge transport device as in claim 1,wherein said drive assembly comprises a single drive motor and aplurality of gears, and wherein said single drive motor drives all ofsaid plurality of gears.
 4. A data cartridge transport device as inclaim 1, wherein said cartridge eject mechanism comprises a plurality ofejection rollers and a gear train, wherein said gear train drives saidplurality of ejection rollers, and wherein said drive assembly drivessaid gear train.
 5. A data cartridge transport device as in claim 1,wherein said clutch assembly comprises: a solenoid; and a pivot armwhich is coupled to said solenoid, said pivot assembly, and saidcartridge eject mechanism.
 6. A data cartridge transport device as inclaim 5, wherein said drive assembly comprises a ring gear, wherein saidcartridge eject mechanism comprises a pinion gear, and wherein saidpivot arm of said clutch assembly is coupled to said cartridge ejectmechanism via a drive shaft on which said pinion gear is mounted, saidclutch assembly bringing said pinion gear into engagement with said ringgear when said clutch assembly engages said drive assembly with saidcartridge eject mechanism.
 7. A data cartridge transport device as inclaim 5, wherein said pivot arm of said clutch assembly is coupled tosaid pivot assembly via a noose which encircles a pivot of said pivotassembly.
 8. A data cartridge transport device as in claim 1, wherein:said drive assembly comprises a first drive gear; and said cartridgeeject mechanism comprises a drive shaft having second and third drivegears mounted axially thereon, said second drive gear engaging saidfirst drive gear and said third drive gear operating a plurality ofejection rollers when said cartridge eject mechanism is engaged withsaid drive assembly.
 9. A data cartridge transport device as in claim 1,wherein: said drive assembly comprises a first drive gear; and saidcartridge eject mechanism comprises a drive shaft having second andthird drive gears mounted axially thereon, said second drive gearengaging said first drive gear and said third drive gear operating acartridge ejection gear train when said cartridge eject mechanism isengaged with said drive assembly.
 10. A data cartridge transport deviceas in claim 1, further comprising a housing, said housing being sizedsimilarly to a cartridge magazine of a cartridge library in which saiddata cartridge transport device operates.
 11. A data cartridge transportdevice as in claim 1, wherein the cartridge sleeve is mounted to thepivot assembly via a channel in the cartridge sleeve and a blade on thepivot assembly, and wherein the blade slides in the channel when theclutch assembly moves between its first and second positions.
 12. A datacartridge transport device as in claim 1, wherein the cartridge sleeveis mounted to the pivot assembly via a blade on the cartridge sleeve anda channel in the pivot assembly, and wherein the blade slides in thechannel when the clutch assembly moves between its first and secondpositions.
 13. A data cartridge transport system, comprising: a firstdata cartridge transport device comprising: a pivot assembly; acartridge sleeve, mounted to said pivot assembly; a cartridge ejectmechanism, operably associated with said cartridge sleeve; and a controlsystem, said control system alternately operating said pivot assembly tothereby pivot said cartridge sleeve, and operating said cartridge ejectmechanism to thereby eject a data cartridge from said cartridge sleeve;and a second data cartridge transport device for receiving a datacartridge ejected from said first data cartridge transport device.
 14. Adata cartridge transport system as in claim 13, wherein said second datacartridge transport device comprises: a second cartridge sleeve; and anactive cartridge-receiving mechanism, operably associated with saidsecond cartridge sleeve.
 15. A data cartridge transport system as inclaim 13, wherein said second data cartridge transport device comprises:a second cartridge sleeve; and an active cartridge eject mechanism,operably associated with said second cartridge sleeve.
 16. A datacartridge transport system as in claim 13, wherein said second datacartridge transport device comprises: a second pivot assembly; a secondcartridge sleeve, mounted to said second pivot assembly; a cartridgeeject mechanism, operably associated with said second cartridge sleeve;and a second control system, said second control system alternatelyoperating said second pivot assembly to thereby pivot said secondcartridge sleeve, and operating said cartridge eject mechanism tothereby receive and reject data cartridges from said second cartridgesleeve.
 17. A data cartridge transport system as in claim 13, whereinthe first data cartridge transport device is mounted within a firstcartridge library, and wherein the second data cartridge transportdevice is mounted within a second cartridge library.
 18. A datacartridge transport system as in claim 13, further comprising a thirddata cartridge transport device, wherein: the third cartridge transportdevice is mounted within a first cartridge library and comprises: anadditional cartridge sleeve; and an active cartridge eject mechanism,operably associated with said additional cartridge sleeve; the secondcartridge transport device is mounted within a second cartridge library;and the first data cartridge transport device is mounted between thefirst and second cartridge libraries, thereby enabling transport of adata cartridge from the first cartridge library to the second cartridgelibrary.
 19. A data cartridge transport system as in claim 13, whereinsaid pivot assembly comprises a pivot that is off-center with respect toan axis of said cartridge sleeve when said control system is operatingsaid pivot assembly.
 20. A method of transporting data cartridgesbetween cartridge libraries, comprising: receiving a data cartridgestored in a first cartridge library; pivoting the data cartridge; andejecting the data cartridge to a cartridge sleeve of a second cartridgelibrary.